function [ny1 ny2] = func_nyk_from_nxyk(nz, nx, CONSTS)

    [nxy1 nxy2] = func_nxyk_from_nz(nz, CONSTS);

    ny1 = sqrt_from_negative_num(nxy1.^2-nx.^2);
    ny2 = sqrt_from_negative_num(nxy2.^2-nx.^2);

end